JP5214664B2 - Timing pulley - Google Patents

Description

  The present invention relates to a motion transmission mechanism that transmits a rotational motion using a timing belt, and more particularly, to a timing pulley used together with a timing belt.

  Conventionally, a rotational motion transmission mechanism composed of a toothed belt such as a timing belt and a timing pulley is a simple and reliable motion transmission means. For example, in a rotational transmission mechanism that drives an auxiliary machine of an engine, etc. Various structures have been put into practical use.

Further, as a further noise reduction, a toothed belt having engagement teeth formed on the inner peripheral surface, and a timing pulley having an engagement portion shaped to engage with the engagement teeth formed on the toothed belt. In the motion transmission mechanism configured, the contact area between the engaging tooth of the toothed belt and the engaging portion of the timing pulley is reduced by providing a groove-like uneven portion parallel to the axial direction in such an engaging portion. As a result, it is possible to reduce the adhesive noise between the toothed belt and the timing pulley, or to discharge air remaining in the engaging portion to the outside via the concavo-convex portion, so that air compression occurs in the engaging portion. Has been proposed to prevent noise from occurring (Patent Document 1).
JP-A-10-141479 JP-A-6-300116

  However, in the timing pulley as in the prior art, in order to make the toothed belt and the timing pulley operate smoothly over a long period of time, for example, the shape of the engaging tooth of the toothed belt and the engaging portion of the timing pulley is involute. In many cases, it has a special shape such as a curved line, and it is necessary to use a special machine tool, and skill is required for processing, which causes a problem of poor workability.

More specifically, as shown in FIG. 8, the engaging portion formed on the timing pulley 500 (or sprocket) is engaged with the engaging tooth TB1 of the toothed belt TB in the conventional timing belt system. It was almost the entire inner surface of 501.
The engaging portion 501 has a sophisticated structure that prevents mutual movement with the surface of the engaging tooth TB1 of the toothed belt TB as in an involute curve, for example. There is a problem that a large manufacturing burden is required due to the need for a machine tool.
Further, when the toothed belt TB and the timing pulley 500 are engaged with each other, there is a problem that air remaining in the vicinity of the bottom of the engaging portion 501 is compressed and often causes noise.

Further, as a mechanism for preventing such noise caused by air compression generated between the toothed belt TB and the timing pulley 500, an engaging portion formed on the timing pulley 500 when meshing with the toothed belt TB is used. It is conceivable that the air 501 quickly escapes to the outside and no air compression occurs near the bottom of the engaging portion 501 of the timing pulley 500 (see Patent Document 1).
In this case, either the engagement tooth TB1 of the toothed belt TB or the engagement portion of the timing pulley 500 is provided with a structure for escaping air such as a groove or an uneven portion. However, there was a problem that it took more time.

  The present invention solves the problems of the prior art as described above, and the technical problem of the present invention, that is, the object of the present invention, is to resonate by mutual movements with different periods in meshing with a toothed belt. An object of the present invention is to provide a timing pulley that is light in weight, has a simple pulley structure, and has excellent workability by greatly reducing noise caused by vibration.

  The invention according to claim 1 is a cylindrical timing hub inserted into a power transmission shaft, a pair of left and right flange members provided at both ends of the timing hub, and a peripheral portion of the pair of left and right flange members. A timing pulley including a plurality of engagement pins that are detachably provided in a straddling state through pin insertion holes arranged along the engagement holes of the toothed belt, and the flange member is connected to the timing hub. The engagement pins are detachably fixed by using bolt fastening means, and the engagement pins are continuously arranged in a unit pitch arranged at different intervals between the engagement pins in a predetermined order in the circumferential direction of the flange member. By arranging in the circumferential direction, the above-described problems are solved.

  In addition to the configuration of the invention according to claim 1, the timing pulley of the invention according to claim 2 is provided with a threaded portion that is screwed into the flange member by a nut at each end of the meshing pin. Thus, the above-described problems are further solved.

  The timing pulley according to a third aspect of the present invention is the timing pulley according to the first aspect or the second aspect, wherein the engagement pin includes a pin-locking small-diameter portion that is locked to the flange member by a retaining ring. By providing at both ends of the pin, the above-described problems are further solved.

  A timing pulley according to a first aspect of the present invention includes a cylindrical timing hub that is inserted into a power transmission shaft, a pair of left and right flange members that are provided at both ends of the timing hub, and a pair of left and right flange members. A plurality of engagement pins arranged in a circumferentially extending manner along the circumferential direction of the flange member of the flange member and meshing with the engagement teeth of the toothed belt. In addition to being excellent, the following effects specific to the present invention are exhibited.

  That is, according to the timing pulley of the first aspect of the present invention, the plurality of engagement pins that are arranged in a straddling state along the circumferential direction on the peripheral portions of the pair of left and right flange members and mesh with the engagement teeth of the toothed belt. By providing, the engagement part that engages with the engagement teeth of the toothed belt is only the engagement pin, and the space inside the engagement pin is connected to the outside, so it is greatly compared with the conventional solid timing pulley In addition to being able to reduce the weight, the closed space between the engaging portion of the timing pulley and the engaging tooth of the toothed belt is eliminated, so that noise caused by air compression generated in such a closed space is generated. It can be with no.

  In addition, the adoption of the engagement pin makes it possible to manufacture the engaging portion of the timing pulley using the engagement pin that can be produced by simple processing. Therefore, processing that uses a machine tool such as a hobbing machine can be performed. This eliminates the need to do so and can greatly improve productivity.

  And, since the engagement pin is detachably provided through the pin insertion hole arranged along the circumferential direction of the flange member, the engagement operation of the engagement pin becomes easier, so the manufacturing process of the timing pulley is reduced. It can be simplified more.

  In addition, when a part of the timing pulley is damaged, it is not necessary to replace the entire timing pulley, and it can be regenerated and used simply by replacing the meshing pin at the damaged part. In addition, waste of materials and the like can be reduced.

Further, since the flange member is detachably fixed to the timing hub using the bolt fastening means, the timing hub and the flange member can be easily assembled by the bolt fastening means. It is possible to dispense with complicated work such as use.
Further, the meshing pins are arranged in the circumferential direction so as to be continuous in a unit pitch arranged in a predetermined order in the circumferential direction of the flange member, thereby engaging with the toothed belt. In this case, mutual motions having different periods occur, so that resonance vibrations generated as a result of the periodic mutual motions can be reduced, and noise resulting therefrom can be greatly reduced.

  According to the timing pulley of the second aspect of the invention, in addition to the effect of the first aspect of the invention, the threaded portion in which the meshing pin is screwed to the flange member by the nut is provided at both ends of the meshing pin. Because it is possible to mount and disengage the engagement pin by screwing and removing the nut, the engagement pin can be fixed to the flange member without loosening, and maintenance work such as replacement of the engagement pin at the time of breakage is simplified. can do.

  According to the timing pulley of the invention according to claim 3, in addition to the effect produced by the invention according to claim 1 or claim 2, the pin locking small diameter portion in which the engagement pin is locked to the flange member by the retaining ring is provided. Since the engagement pins are provided at both ends of the engagement pin, the engagement pin is attached only by fitting a retaining ring to the pin locking small diameter portion of the engagement pin. Installation work can be simplified.

The schematic diagram of the timing pulley which is a reference example for helping an understanding of the present invention. The front view of the timing pulley shown in FIG. FIG. 3 is an AA cross-sectional view of the timing pulley shown in FIG. 2. The elements on larger scale of a meshing pin mounting part. The elements on larger scale which show the different aspect of a meshing pin mounting part. Operation | movement explanatory drawing of the timing pulley shown in FIG. Operation | movement explanatory drawing of the timing pulley which is an Example of this invention. The front view of the timing pulley of a prior art. BB sectional drawing of the timing pulley of a prior art. Operation | movement explanatory drawing of the timing pulley of a prior art.

  The present invention is arranged along a cylindrical timing hub to be inserted into a power transmission shaft, a pair of left and right flange members provided separately from both ends of the timing hub, and peripheral edges of the pair of left and right flange members. In a timing pulley having a plurality of engagement pins that are detachably provided in a straddling state through the pin insertion holes and that are engaged with engagement teeth of the toothed belt, the flange member is attached to and detached from the timing hub using bolt fastening means. The engagement pins are arranged in the circumferential direction so as to be continuous in unit pitches arranged with different intervals between the engagement pins in a predetermined order in the circumferential direction of the flange member. If the noise caused by resonance vibration is greatly reduced by the mutual movement with different periods in meshing, the pulley structure is light and simple and excellent in workability. Specific embodiments of, and may be any of those.

  That is, the material itself such as the timing hub, the flange member, or the engagement pin constituting the timing pulley may be made of metal as is conventionally known, but the strength required for the motion transmission mechanism to be applied is increased. Accordingly, it may be formed of a synthetic resin material such as FRP or engineering plastic, or may be a combination of a metal part and a synthetic resin part.

  Further, the toothed belt used together with the timing pulley can be formed of the same material as that used in the past, and may be a synthetic resin material reinforced with a wire such as steel wire or Kevlar.

  Further, as the bolt fastening means, any means may be adopted as long as it can be fastened securely without loosening, such as bolts and screws.

A timing pulley which is a reference example (hereinafter referred to as “reference example”) for helping understanding of the present invention will be described with reference to FIGS.
Here, FIG. 1 is a schematic diagram of a timing pulley of a reference example, FIG. 2 is a front view of the timing pulley shown in FIG. 1, FIG. 3 is a sectional view of the timing pulley shown in FIG. 3 is a partially enlarged view of the engaging pin mounting portion in FIG. 3, FIG. 5 is a partially enlarged view showing different aspects of the engaging pin mounting portion in FIG. 3, and FIG. 6 is an operation explanatory view of the timing pulley shown in FIG. .

A timing pulley 100, which is a reference example for helping understanding of the present invention, is used in, for example, a timing belt system used for driving an auxiliary machine of an engine.
The timing pulley 100 includes a cylindrical metal timing hub 110 into which a power transmission shaft is inserted. A circular flange member 120 is attached to each end of the timing hub 110 in the axial direction by four bolts 140. It is provided freely.

The engagement pin 130 is disposed in a straddling state between a pair of flange members 120 provided on the left and right of the timing hub 110.
As shown in FIGS. 2 and 3, the engagement pin 130 is detachably provided in a plurality of pin insertion holes 121 arranged along the circumferential direction at the peripheral edge portions of the pair of flange members 120.
The engagement pin 130 has a cylindrical shape as a whole, and in the reference example of the present invention, slit-shaped pin locking small-diameter portions 131 are provided in the vicinity of both ends corresponding to the width of the pair of flange members 120. .
When mounting the engagement pin 130, the engagement pin 130 is inserted into the pin insertion hole 121 from one side of the pair of flange members 120, and both ends of the engagement pin 130 protrude from both sides of the pair of flange members 120. The engagement pin 130 is locked by fitting a retaining ring 150 into the pin locking small diameter portions 131 provided at both ends.

Further, in the reference example of the present invention, as shown in FIG. 4, the engagement pin 130 is locked to the flange member 120 by the retaining ring 150. However, as shown in FIG. In addition, screw portions 132 are provided at both ends of the engagement pin 130, and when the engagement pin 130 is attached, the engagement pin 130 is inserted from one side of the pair of flange members 120, and both ends are a pair of flange members 120. Alternatively, the nut 160 may be fastened and fixed to the screw portions 132 at both ends of the engagement pin 130 at the positions protruding from both sides.
As described above, when the engagement pin 130 is fastened using the nut 160, the engagement pin 130 is fixed to the flange member 120 without loosening, and rattling or the like in the pin insertion hole 121 of the engagement pin 130 is eliminated.

  As the toothed belt TB used by being wound around the timing pulley 100, a conventionally known wire core whose core wire is covered with a synthetic resin can be used, and the inner surface engages with the engagement pin 130 of the timing pulley 100. Engagement teeth TB1 are provided.

  As shown in FIG. 4, the timing pulley 100 is used with a toothed belt TB wrapped around its outer periphery, and the engaging tooth TB1 of the toothed belt TB is engaged between the front and rear engaging pins 130 and operates reliably. It is transmitted.

The most characteristic feature of the reference example of the present invention is that the timing pulley 100 is engaged only with the side surface of the cylindrical engagement pin 130 provided around the timing pulley 100 so that the engaging tooth TB1 of the toothed belt TB is engaged. This is the point.
That is, only the cylindrical surface of the engagement pin 130 engages with the engagement teeth TB1 of the toothed belt TB, and the portions between the engagement pins 130 and the inner side of the engagement pin 130 in the timing pulley 100 are flanged on both sides. The part is an open space that communicates with the outside as long as the member 120 exists, and a part that engages with the toothed belt TB simply by producing a cylindrical engagement pin 130 and mounting it on the flange member 120. Is produced.

  Further, unlike the conventional timing belt system, a closed space is not formed between the surface of the engaging tooth TB1 of the toothed belt TB and the engaging portion of the timing pulley 100. It is unrelated to the phenomenon such as air compression.

  The timing pulley 100, which is a reference example of the present invention thus obtained, is a pair of left and right cylindrical timing hubs 110 that are inserted into the power transmission shaft and spaced apart at both ends of the timing hub 110. Flange member 120 and a plurality of engagement pins 130 that are arranged in a straddling state along the circumferential direction at the peripheral edge portions of the pair of left and right flange members 120 and mesh with the engagement teeth TB1 of the toothed belt TB. As a result, the timing pulley using the conventional heavy timing pulley is free from noise caused by air compression at the engaging portion with the toothed belt as generated in the conventional timing pulley 500, and using the conventional heavy timing pulley. It has a lighter pulley structure than

  Further, since the timing pulley 100 is simply manufactured by assembling parts having a simplified shape and structure such as the timing hub 110, the flange member 120, or the engagement pin 130, forging, cutting, etc. from a conventional metal material Compared to the fact that the timing pulley was manufactured by applying the above process, the manufacturing process is greatly simplified.

Next, a timing pulley 200 which is an embodiment of the present invention (hereinafter referred to as “embodiment”) will be described with reference to FIG.
The embodiment of the present invention corresponds to the same member as the timing pulley 100 of the reference example since the other specific configuration is the same as the reference example described above except that the mounting mode of the engagement pin 130 is different. Therefore, the reference numerals of the 200th series are attached, and the duplicate description is omitted.

FIG. 7 is an operation explanatory diagram of the timing pulley 200 according to the embodiment of the present invention.
In the timing pulley 200 according to the embodiment of the present invention, for example, three uniting pins 230 form one unit pitch P.
More specifically, the interval A is between the engagement pin 231 and the engagement pin 232, the interval B is between the engagement pin 232 and the engagement pin 233, and the interval between the engagement pin 233 and the next engagement pin 231 is. A unit pitch P is formed by the three engagement pins 230 and three different interval portions, and the timing pulley 200 is configured by arranging the unit pitches P in the circumferential direction.

  In the timing pulley 200 according to the embodiment of the present invention, since the interval between the engagement pins 230 is configured as described above, the regularity of the mutual movement between the engagement pins 230 and the toothed belt TB is lost. The resonance vibration of the belt TB is greatly reduced.

In particular, the problem of resonance vibration as described above can be solved by simply changing the circumferential interval of the engagement pins 230 attached to the flange member 220 and arranging the unit pitches P in the circumferential direction. Is done.
In the timing pulley 200 according to the embodiment of the present invention, there are three types of intervals between the engagement pins 231 to 233. However, the interval is not particularly limited to three types, and four or more types are provided by four or more engagement pins 230. The unit pitch P can also be configured by providing an interval of.

  Further, if the structure eliminates the periodicity in the interaction between the timing pulley 200 and the toothed belt TB, not only the arrangement interval of the engagement pins 230 is changed, but also the diameter and shape of the engagement pins 230 are changed. In addition, various structures that make the meshing structure of the meshing pin 230 and the engaging tooth TB1 irregular can be adopted as appropriate in the circumferential direction.

  The timing pulley 200 according to the embodiment of the present invention thus obtained includes a cylindrical timing hub 210 to be attached to the power transmission shaft, and a pair of left and right provided at both ends of the timing hub 210. Flange member 220, and a plurality of engagement pins 230 that are arranged in a circumferentially extending state along the circumferential direction of the pair of left and right flange members 220 and mesh with the engagement teeth TB1 of the toothed belt TB. In addition, the engagement pins 230 are arranged in the circumferential direction so as to be continuous with unit pitches P arranged at different intervals in a predetermined order in the circumferential direction of the pair of left and right flange members 220. In addition to the effect produced by the timing pulley 100 of the reference example, noise caused by the resonance vibration of the toothed belt TB can be greatly reduced.

  Furthermore, since the mechanism for eliminating the resonance vibration of the toothed belt TB can be achieved by a simple method of simply changing the circumferential interval of the engagement pin 230, the manufacturing process is simplified and the workability is greatly improved. The effect is enormous, as it can be improved.

100, 200 ... Timing pulley 110, 210 ... Timing hub 120, 220 ... Flange member 121 ... Pin insertion hole 130, 230, 231, 232, 233 ... Engagement pin 131 ... Pin Small diameter portion 132 for locking ... Screw portion 140 ... Bolt 150 ... Retaining ring 160 ... Nut P ... Unit pitch TB ... Toothed belt TB1 ... Engaging tooth 500 ...・ Timing pulley 501 ... engaging part

Claims (3)

A cylindrical timing hub to be inserted into the power transmission shaft, a pair of left and right flange members provided separately from both ends of the timing hub, and a pin insertion hole disposed along the peripheral edge of the pair of left and right flange members In a timing pulley provided with a plurality of engagement pins that are detachably provided in a straddling state via the engagement teeth of the toothed belt,
The flange member is detachably fixed to the timing hub using bolt fastening means,
The timing pulley according to claim 1, wherein the engagement pins are arranged in the circumferential direction so as to be continuous in a unit pitch arranged in a predetermined order in the circumferential direction of the flange member with the intervals between the engagement pins being different.   2. The timing pulley according to claim 1, wherein each of the meshing pins includes a threaded portion that is screwed into the flange member with a nut at each end of the meshing pin.   3. The timing according to claim 1, wherein each of the engagement pins includes a pin-locking small-diameter portion that is engaged with the flange member by a retaining ring at both ends of the engagement pin. Pulley.

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